The prior art is replete with cementing compositions.
Specifically, U.S. Pat. No. 3,168,139 to H. T. Kennedy, et al; 3,499,491 to R. E. Wyant, et al; 3,557,876 to A. Tregasser; 3,887,009 to G. L. Miller et al; and 4,176,722, William N. Wilson disclose well cement compositions which have been formed, at least in part, by well drilling fluids. Other art is discussed and abstracted in the Information Disclosure Statement accompanying this application.
Many prior art efforts to convert drilling fluid to cement material have posed problems in causing increased viscosity and flocculation and slow setting of the cement. In the co-pending application Ser. No. 07/131,838, given docket number DP 50-6-980A and Ser. No. 07/342,421, docket number DP 50-6-980B both entitled "Cementing Oil and Gas Wells Using Converted Drilling Fluid", Wilson et al, there was described in more nearly complete detail the problems frequently encountered. Also in application Ser. No. 07/393,546, entitled "NEW CEMENT ACCELERATIONS"; inventors Robert B. Carpenter and Williams N. Wilson, assigned to the assignee of this application, there was also disclosed some of the problems with other accelerators for the cement slurry.
Accordingly, it is an object of this invention to provide an improved composition and method of cementing a well penetrating subterranean formations in which a large portion of the drilling fluid has been converted to cementitious slurry for use to prevent having to dispose of the drilling fluid and all of the problems related thereto; as well as provide a cure for effecting a satisfactory set cement in an acceptable time interval.